Slow Synchronization

Basics

Since flash light is usually stronger than the surrounding ambient light, when you shoot with flash light in a low light environment, it is likely that only your main subjects are illuminated properly. The left image below was taken around midnight with flash on. The distance between the camera and the subject is about six yards. As a result, only the sign, which is reflexive, and the pole are visible.

Without Slow Synchronization	With Slow Synchronization
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This problem can be overcome using slow synchronization. Slow synchronization means after the flash fires, the shutter stays open for a little longer. In this way, the flash light illuminates main subjects and the slow shutter speed helps capture the background. The right image above shows the effect of slow synchronization. As you can see, the background pops up and the snow in the foreground looks more natural.

The following is another example. The left image was taken using the internal flash in a forest. Like the left image above, only the foreground and the main subject re illuminated. The right image was taken with slow synchronization turned on. As you can see, the background is also captured. Since the internal flash does not reach very far, the use of slow synchronization usually provide a way to produce image with better color saturation if subjects are near the end of reach of the internal flash. The images below illustrate this well.

Without Slow Synchronization	With Slow Synchronization
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Slow synchronization can also make an image to look more natural. The left image below uses flash without slow synchronization. It does not look like the actual scene which should be warmer. With slow synchronization, we have the right image. Now, the foreground is illuminated by the flash, and the background, which is illuminated by a table-top lamp, becomes warmer and looks more natural.

Without Slow Synchronization	With Slow Synchronization
Click on the image to see a larger one

Operation

To activate slow synchronization in both A-REC and M-REC, use the flash setting button on the back panel:

Press this button until SLOW appears on both the LCD panel and the LCD monitor as shown below. Once SLOW appears, all subsequent shots using flash will use slow synchronization.

Control Panel	LCD monitor

After activating slow synchronization, it stays until the flash mode is changed to another. In A-REC, turning off the camera deactivates slow synchronization. However, in M-REC, turning off the camera does not deactivate slow synchronization. Slow synchronization can only be deactivated by setting the flash mode to another.